Donald Trump went on and on for nearly an hour, basking in his latest wins, razzing his rivals, slinging steaks — literally offering red meat — and repeatedly thanking a bygone Yankees legend for his endorsement. Not for one second did the television networks, even with Hillary Clinton speaking at the same time, cut away.

It doesn’t matter what Trump says, only that he continues to talk.

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What less than a year ago looked to be the most talented Republican field in decades has been laid to waste by a candidate whose stream-of-consciousness monologues, opaque policy positions and racially charged populist nationalism have only made his reality show of a campaign — a hybrid of “Seinfeld” and “All in the Family” — impossible for rivals to compete with and too compelling for the country to ignore.

Trump’s ultimate test, however, is still one week away.

After adding to his delegate lead with victories in Michigan, Mississippi and Hawaii Tuesday night, Trump looked and sounded like a candidate who knows he can’t be beaten. He carries more momentum than any of his rivals into critical March 15 contests in Ohio and Florida, two winner-take-all states where John Kasich and Marco Rubio, respectively, will be making their last stands — not in hopes of eventually winning the nomination outright, just surviving to a July floor fight at the RNC convention.

Winning even in the face of hardening GOP establishment opposition, Trump reveled in being so bulletproof. "I want to thank the special interests and the lobbyists, because they obviously did something to drive up my numbers," Trump joked to supporters gathered in Jupiter, Florida. Attempting to be more presidential, he went easy on Mitt Romney, the 2012 nominee who last week laid out a point-by-point takedown of Trump that proved to be unpersuasive at the polls.

Rubio had such a bad night, watching his support crater over the past week and falling short of the 15 percent threshold necessary to win delegates in Michigan and Mississippi, that Trump at first resisted — for a while, anyway — mocking him. But he offered his own analysis, as self-justifying as it was indisputably true, that his rival’s collapse resulted from his decision two weeks ago to try to go to toe-to-toe trading puerile insults with himself. After polling around the 20 percent mark in Michigan just weeks ago, Rubio fell to just 9 percent in the final results. His 5 percent showing in Mississippi was even more disastrous.

“He got very hostile a couple weeks ago,” Trump said of Rubio. “Hostility works for some people; it doesn’t work for everyone.”

It’s a warning Trump has sounded before, noting, “Every single person who’s attacked me, they’re gone.” And he has the scalps to prove it: Rick Perry’s, Lindsey Graham’s, Jeb Bush’s and, perhaps soon, Rubio’s. The ultimate alpha dog, Trump refuses to be out-bullied, having withstood his rivals’ best punches for months and laid them out with his signature uppercut —crippling characterizations like the “low energy” tag he hung on Bush and the “Little Marco” moniker he’s now sticking to Rubio.

While Rubio’s campaign is tuning out the pundits writing their candidate’s political obituary and remaining laser-focused on winning Florida, a number of establishment Republicans acknowledge that the senator’s string of poor showings "make it harder," according to one Rubio financier. Some of the senator’s donors are now openly discussing whether Rubio should even stay in the race through next week and risk a humiliating defeat in his home state; and the top of Drudge Report Tuesday night offered a picture of a tiny Rubio under the banner headline: “The incredible shrinking campaign.”

But the March 15 primaries in Florida, Ohio and Illinois — not Tuesday’s contests in states where anti-Trump ads were scarce by comparison and Rubio really didn’t bother to compete — will serve as the final verdict on whether Trump is truly bulletproof.

In the next seven days, Trump will face a barrage of negative attack ads the likes of which he hasn’t had to endure to date. For all the property he owns in Florida, he will not own the state’s airwaves.

According to ad tracking services, Trump's campaign has put $1.3 million behind a statewide network and cable television ad buy to ensure that his 60-second spot attacking Marco Rubio is seen across all of the state’s eight media markets. Corey Lewandowski, Trump’s campaign manager, disputed that figure, saying only that the campaign is spending “significantly” more than that on Florida television ads this week.

But Trump is going to be underwater overall, with a number of outside groups spending more than $15 million so far over the same period in an effort to prevent him from winning Florida's 99-delegate windfall, which could enable him to ultimately secure the 1,237 delegates necessary to win the GOP nomination outright.

Trump’s three chief antagonists — Our Principles PAC, the group established just to fight Trump, Club For Growth and American Future Fund — are poised to spend more than $12 million between them on television ads attacking Trump in the run-up to Tuesday’s vote, according to ad-tracking firms.

And while Rubio’s campaign isn’t currently spending any money on TV ads, the super PAC backing him, Conservative Solutions PAC, has reserved $4 million in advertising through next Tuesday night.

Trump’s campaign could increase its ad buy in the days ahead. But it’s clear the billionaire, who has led the GOP primary field for months and proved remarkably immune to his opponent’s attacks, is finally facing a serious and sustained deluge of negative TV ads for the first time.

And if that doesn’t dent his support, “nothing will,” admits Katie Packer, the former top Romney aide who founded Our Principles PAC. “But it hasn’t been tried yet.”

If Trump does lose Florida, the best this assault will likely do is prolong the nomination fight until the RNC convention in July. Then, the vexing question for the anti-Trump forces becomes: How can the GOP justify denying the nomination to the guy who got the most votes?

“The establishment waited too long,” said one GOP operative aligned with another campaign who requested anonymity to speak freely. “All these other candidates, they’re just fighting to position themselves as the clear No. 2 option heading into the convention.”